using System;
using System.Runtime.ConstrainedExecution;

namespace VRage.Library.Collections
{
	internal static class HashHelpers
	{
		public static readonly int[] primes = new int[72]
		{
			3, 7, 11, 17, 23, 29, 37, 47, 59, 71,
			89, 107, 131, 163, 197, 239, 293, 353, 431, 521,
			631, 761, 919, 1103, 1327, 1597, 1931, 2333, 2801, 3371,
			4049, 4861, 5839, 7013, 8419, 10103, 12143, 14591, 17519, 21023,
			25229, 30293, 36353, 43627, 52361, 62851, 75431, 90523, 108631, 130363,
			156437, 187751, 225307, 270371, 324449, 389357, 467237, 560689, 672827, 807403,
			968897, 1162687, 1395263, 1674319, 2009191, 2411033, 2893249, 3471899, 4166287, 4999559,
			5999471, 7199369
		};

		internal const int HashPrime = 101;

		public const int MaxPrimeArrayLength = 2146435069;

		[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
		public static bool IsPrime(int candidate)
		{
			if (((uint)candidate & (true ? 1u : 0u)) != 0)
			{
				int num = (int)Math.Sqrt(candidate);
				for (int i = 3; i <= num; i += 2)
				{
					if (candidate % i == 0)
					{
						return false;
					}
				}
				return true;
			}
			return candidate == 2;
		}

		[ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
		public static int GetPrime(int min)
		{
			if (min < 0)
			{
				throw new ArgumentException();
			}
			for (int i = 0; i < primes.Length; i++)
			{
				int num = primes[i];
				if (num >= min)
				{
					return num;
				}
			}
			for (int j = min | 1; j < int.MaxValue; j += 2)
			{
				if (IsPrime(j) && (j - 1) % 101 != 0)
				{
					return j;
				}
			}
			return min;
		}

		public static int GetMinPrime()
		{
			return primes[0];
		}

		public static int ExpandPrime(int oldSize)
		{
			int num = 2 * oldSize;
			if ((uint)num > 2146435069u && 2146435069 > oldSize)
			{
				return 2146435069;
			}
			return GetPrime(num);
		}
	}
}
